Vintage setup question, DAC loudness (NAD 106 & NAD C270)

(wrong forum apologies, how do I delete this?)

Hi, recently resurrected an old NAD C270 amp and fond a slightly newer NAD 106 preamp, hooked them up to a DAC (Raspberry/iQuadIO DAC+ running Volumio) and it sounds really good to me. There's one issue with loudness I'm wondering if I can benefit from the collective wisdom.

- After getting the amp repaired, hooked up the DAC thru fixed input. It is VERY loud and amp went into protection mode. Seems the DAC is a "high gain device" and can not go over 15% on app volume control. Tried the variable input dialed way down so app volume control can go up to 50%, but any push on loudness would again trigger protection mode.

- After adding the preamp things worked much better. With the preamp in between (thru fixed input) lights stayed green and sounded very pleasant. However still can not turn the volume in the app past 75% with quarter of a turn on preamp volume, with more spirited listening at a third of turn.

Did not think volume range would be so limited with the preamp, or the fault lies with the DAC? Do you feel this setup is optimal? Should I connect thru variable input on the amp so I can make more use of the volume range?

Thanks!

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